JAN1N4956C

JAN1N4956C Application Field and Working Principle

The JAN1N4956C diode is a single Zener diode, specifically a low current Zener diode, from Fairchild Semiconductor. The device is housed in a DO41 package and is capable of handling a maximum power dissipation of 500mW.

The Zener breakdown voltage of the JAN1N4956C is 5.1 volts, and it has a standard 5-percent tolerance. The device has a maximum reverse current of 100uA, allowing it to be used in a noisy environment. Further, it has a maximum reverse leakage of 30nA at 5.1V.

Because the JAN1N4956C is a Zener diode, the device can be used in two main applications: voltage limiter and overvoltage protection. In voltage limiter applications, the device is connected in parallel with a load and when the peak voltage exceeds the Zener breakdown voltage, a large current flows through the Zener diode, limiting the voltage. In overvoltage protection applications, the device is connected in series with a load and it acts as a short circuit when the voltage exceeds the Zener breakdown voltage protecting the load from the high voltage.

Working Principle

The working principle of the JAN1N4956C diode is based on the phenomenon known as Zener breakdown. This occurs when an electric field of high enough intensity is applied across a junction of two materials of different conductivity. The junction is said to be “reverse-biased” in this case, meaning current will flow in the opposite direction of conventional current. As a result, the electric field intensity increases across the junction, which forms a depletion region. When the reverse breakdown voltage of the junction is reached, a space charge is formed, allowing the current to flow freely across the junction.

Because the electric field intensity is controlled by the voltage applied to the junction, the current flow is also controlled. This phenomena leads to the ability of a Zener diode to be used to limit voltage, or as a protection against overvoltage. Since the device has a low forward voltage drop, it can be used as a high-efficiency voltage limiter or overvoltage protector in many applications.

Conclusion

The JAN1N4956C Zener diode is a general purpose low current Zener diode from Fairchild Semiconductor. The device has a 5.1V Zener breakdown voltage and a 5-percent tolerance, making it suitable for many applications. The device is most commonly used as either a low-efficiency voltage limiter or an overvoltage protector, depending on its configuration. The JAN1N4956C is able to provide good performance due to its low forward voltage drop, making it a reliable choice for many applications.